Apparatus for producing single-and/or multi-layer tablets



March 2, 1965 A. WICHART 3,171,356

APPARATUS FOR PRODUCING SINGLE- AND/OR MULTI-LAYER TABLETS Filed March20, 1963 .70 van in r: flifred Wat/earl United States Patent 0 3,171,366APPARATUS FOR PRODUCING SINGLE- AND/0R MULTI-LAYER TABLETS AlfredWichart, Vienna, Austria, assignor to Wilhelm FettePriizisionswerkzeugfabrik, Schwarzenbek, near Hamburg, Germany FiledMar. 20, 1963, Ser. No. 266,752 Claims priority, application Germany,Mar. 22, 1962, F 36,349 3 Claims. (Cl. 107-17) The present inventionrelates to an improved apparatus for producing singleand/ or multi-layertablets.

Tablet making machines are known having a rotary turret and wherein thematrices or moulds pass beneath a filling device which consists of afilling shoe or box to which the material being handled is continuouslysupplied by gravity from a funnel. The material being handled passesfrom the fixedly mounted filling shoe into the matrices of a horizontalrotating matrix wheel and is then compacted by means of plungers to formtablets. The rotary speed of the matrix wheel and thus the number ofarticles which can be produced in a given time is obviously limitedbecause if the speed is too high the matrices are only incompletelyfilled with material so that the tablets produced are of low anduncertain weight.

It is an object of the present invention to overcome this disadvantageby filling the matrices intermittently and compacting the material onlyat those times when the material is being moved past the matrices.

The invention is based on recognition of the fact that with the knownfilling devices the relative speed between the material to be compactedand the matrix wheel is the same as the speed of the matrix wheel. Sincea definite relative speed, varying according tothe nature of thematerial being handled, should not be exceeded for satis factory fillingof the matrices, the present invention provides that the material to becompacted shall be moved in the same direction whereby a furtherincrease in the matrix speed is possible, without the relative speedfalling outside of the limits within which exact filling is possible.

This is permitted according to the invention by arranging the fillingdevice as a ring-shaped filling frame which extends concentricallyaround the whole matrix wheel in the region of the matrices. As a resultof the construction of the device in the form of a ring-shaped frame thematerial to be compacted and supplied to the matrix wheel is no longerheld stationary at one point, as when using a rigidly mounted fillingshoe, but participates in the movement of the matrix wheel although at alower speed, the difierence providing the relative speed which enablesthe matrices to be filled. The material being handled is swept towardsand away from the matrices by means of suitably placed guide bladesattached to the filling device, the matrices passing beneath these guideblades which thus also serve to strike off the material collecting inthe matrices. By means of this deflection or striking ofl and by windageeffects the press material is slightly retarded as regards its speedderived from the matrix wheel so that it moves with a small relativespeed over the matrix wheel. Thereby the matrices are alwayssufliciently filled even at high rotary speeds of the matrix wheel.

The material to be filled into the matrices is supplied by one or moresupply funnels provided at certain points of the frame-like fillingdevices and is constantly made up as required.

If several materials must be handled for the production ofmultiple-layer or coated tablets, which consist of powder, granularmaterial or pre-compacted tablet cores, this can be obtained in a simplemanner by providing additionally two or more ring zones for the variousmaterials,

which zones are associated with corresponding sweeper blades ordeflectors.

The main constructional parts of one example of the invention areillustrated diagrammatically in the accompanying drawing, wherein:

FIG. 1 is a plan view showing a rotary table carrying matpices or mouldswith a stationary filling frame above it for a filling device suppliedwith two different pressing materials, and

FIG. 2 is a section on the line A-B of FIG. 1.

Referring to the drawing, ring-shaped filling zones are formed above thesurface of a rotary wheel 2 provided with a concentric series ofmatrices 1 and driven in the horizontal plane in the direction of thearrow P, these filling zones being formed by exchangeable stationaryringshaped walls 3, 4 and 5 substantially in contact with the upper faceof the wheel 2 and provided with obliquely placed deflector blades 6 andsegmental guide walls 7 which latter are concentric with the circularwalls 3, 4 and 5. The blades 6 sweep the tablet forming materialsbetween the walls 3, 4 and 5 towards and away from the matrices 1 andcause such material to rotate with the wheel 2 but at a slightly lowerspeed.

In the disclosed constructional example the production of multiple-layertablets is intended and a first material G to be compacted and a secondmaterial G to be compacted is supplied to the wheel 3. These materialswhich may be, for example, in the form of powders are suppliedseparately from supply funnels, not shown, into filling zones defined bythe walls 3, 4 and 5 and wall segments 7, over the sector S indicated onthe drawing.

A part of the material G is swept towards the matrices 1 by one of theblades 6 directed outwardly of the wall 5, while the material G isinitially merely carried on ward by the rotating matrix wheel 2. Thecentral wall 4 has inwardly and outwardly directed blades 6, the firstof which sweeps the material G away from the matrices and in thefollowing sector S it is held away by means of a segmental wall 7. Thematerial remaining in the matrices 1 is then pre-cempacted in thissector region by means of a plunger, not shown.

The material G carried with the matrix wheel 2 now runs against a firstsweeper blade 6 on the outer wall 3 whereby it passes into the region ofthe matrices over the sector S A portion of the material G is placedupon the pie-pressed material G in the matrices 1, while the excessamount of material G is pushed away by means of a following outwardlydirected sweeper blade or de flector 6 on the wall 7. In the followingsector a further compacting takes place.

On the further rotary movement of the matrix wheel 2 the material G isswept by reason of the blade 6 towards the matrices over the region of asector 8., whereby again a partial amount of this material flows intothe matrices 1. In the following sector S there is a further compacting.

The material G carried with the matrix wheel from the region of thesector S up to the end of the sector S now passes into the region of thesector S and thus again and finally comes towards the already nearlyfinished tablets T (FIG. 2) in the matrices 1.

The excess amount of material G is then deflected again by the blades 6or deflector walls 7 and passes through the final sectors S7 and S andthence to the first sector S.

The excess amount of material G passes from the end of the sector S overthe sectors S and S and S again in the same way to the first sector S.

The final compacting occurs in the sector S and in the sector S finishedmultiple-layer tablets T are lifted out of the matrices 1 above thelevel of the wheel 2 by a bottom plunger 8 (FIG. 2), as far as the levela of a guide plate 9 and they are then swept onto the guide plate 9 byan oblique extension of the guide wall 7 between sector 5 and sector S.

It will be understood that instead of compacting several powderedmaterials on the Wheel, it would for example also be possible to employpreviously compacted tablet cores which are pressed together with layersof a powdered material, thus forming additional layers of the tablet;

What I claim is: 1. An apparatus for producing tablets comprising arotary table provided with a concentric series of tabletformingmatrices, means for supplying two tablet-formprising plungers arrangedin a' circular path, said ringshaped zones being concentric to'thematrices and having blades'at several points serving as deflectors,means for guiding the'materials to be compacted at these points out ofthe region of the matrices, then past such matrices, then again into theregion of such matrices, to effect a filling of the same, and meanswhereby at those points at which the material-is movedaway from thematrices the mat'erial'already in the matrices 'is compressed, thetablet-forming material being carried around on the surface of the tableat a speed less than the speed of the table.

3. An apparatus for producing tablets, comprising a ro- V tary tableprovided with a concentric series of tablet-formsaid inner and outerguide walls and having sweeper blades directed inwardly and outwardlyalternately to cause said tablet-forming materials to successively clearsaid matrices, short segmental guide walls forming an extensionto'selected sweeper blades to define a segmental portion where notablet-forming material can pass towards the matrices, means to compactthe material in said matrices over said segmental portions, and a guideplate lying at'a level above the table surface for removal of completedtablets in a path lying'over. the second table"- forming material. K V t2. An apparatus for producing tablets, comprising a rotary tableprovided with a concentric series of tabletforming matrices, means forsupplying a tablet-forming 7 material to the surface of said table,circular guide walls arranged above said rotary table to definering-shaped zones adjoining the path'of said matrices, and a device forcompacting the material into the matrices and coming matrices, means forsupplying a tablet-forming material to the surface of said table,circular guide walls arranged above said rotary table to definering-shaped zones adjoining the path of said matrices, and a device forcompacting the material into the matrices and comprising plungersarranged in a circular path, said ring-shaped zones being concentric tothe matrices and having blades at several points serving as deflectors,means for guiding the materials to be compacted at these points out ofthe region of the matrices, then past such matrices, then again into theregion of such matrices, to effect a filling of the same, andmeauswhereby at those points at which the material is moved away from thematrices thematerial already in the matrices is compressed, said ringzones being formed by interchangeable circular walls, the tabletformingmaterial being carried around on the surface of the tableat a speed lessthan the speed of the table.

References Cited by the Examiner UNITED STATES PATENTS CHARLES'A.WILLMUTH, Primary Examiner.

1. AN APPARATUS FOR PRODUCING TABLETS COMPRISING A ROTARY TABLE PROVIDED WITH A CONCENTRIC SERIES OF TABLETFORMING MATRICES, MEANS FOR SUPPLYING TWO TABLET-FORMING MATERIALS TO THE SURFACE OF SAID TABLE, COMPRISING INNER AND OUTER ANNULAR GUIDE WALLS TO DEFINE ANNULAR SURFACES ADAPTED TO RECEIVE SAID TWO TABLET-FORMING MATERIALS, INWARDLY DIRECTED SWEEPER BLADES ON THE OUTER WALL TO SWEEP A FIRST TABLET-FORMING MATERIAL TOWARDS THE MATRICES, OUTWARDLY DIRECTED SWEEPER BLADES ON THE INNER WALL TO SWEEP A SECOND TABLET-FORMING MATERIAL TOWARDS THE MATRICES, AN INTERMEDIATE GUIDE WALL DISPOSED BETWEEN SAID INNER AND OUTER GUIDE WALLS AND HAVING SWEEPER 